In this book, Michael Cassidy argues that the built environment should be designed to last physically for a very long time, saving on valuable material resources. By incorporating flexibility and adaptability into every design, buildings remain functionally useful for as long as they last without the need for wasteful demolition. This approach, which he calls Double-Design, has two complementary consequences. Firstly, design must accommodate changing uses beyond the initial one. Secondly, the users of buildings would be enabled to play their full part in ensuring the usefulness of buildings for as long as they last physically. Through the assessment of compatibilities of the physical requirements for buildings serving different uses over time, this book suggests an approach that establishes a long-life infrastructure within which shorter-life and recyclable material may be used in the fit-out to serve each successive use. Over time, the implementation of Double-Design would provide buildings that are more suited to the changing needs of the future. Guided by sixty years of professional experience as an architect, planner and teacher, Dr. Cassidy considers the underlying assumptions that provide the present context for design and construction. Building upon the work of many scholars and practitioners, he suggests that Double-Design could contribute to the reinvigoration of architecture by keeping it grounded in serving human needs. This is essential reading for practising architects, those entering the profession and anyone interested in the built environment's future. This book is considered an important contribution to the debate about the future of architecture in the new era of information.